This protocol participates in a national study in which we measure islet cell antibodies (ICA) in first degree relatives of subjects with IDDM to detect those at risk to develop IDDM. Those with hith titers will be given IVGTT to measure first phase insulin release (FPIR) and those failing this test will either serve as controls or be given IV/subcutaneous insulin therapy to see if such treatment can delay or prevent their development of clinical diabetes.